It is now commonplace to read Locke in his historical context, recognizing that his writings share the impetus of a common set of political crises. A marginal note in the copy of the Essay Concerning Human Understanding owned by Locke's friend James Tyrell intimates that the Essay originated in a disagreement over morality and revealed religion between friends, a disagreement attested to by Locke himself. The Essay, Locke writes, was begun “but for my own information, and the satisfaction of a few friends… . I should tell thee that five or six friends meeting at my chamber, and discoursing on a subject very remote from this, found themselves quickly at a stand, by the difficulties that rose on every side (EHU epistle.8). If we are to believe Locke, his investigation of epistemology springs from disagreements about morality, faith, and the foundation of assent, not questions of science, his comments about Boyle, Newton, and under-laboring notwithstanding (EHU 1.1.2). Thus, if the Essay is an exercise in brush clearing, it is much more about undermining religious and moral dogmatism than about making space for a new science. Locke understood “the relevance of his theory of knowledge to the problems and debates on morality and religion engaged by his friends and associates.” Of course, were these debates merely between friends, there would be very little emphasis placed on Locke's Essay; it matters because these arguments were the common coin of seventeenth-century English political life, the sparks ready to kiss faction to flame. Locke's epistemology, then, was intended to upset and to have “a disturbing effect upon the traditional moral and religious beliefs.”

Locke's England is threatened by religious conflict, and the Essay serves the political purpose of providing an account of understanding and assent that problematizes easy recourse to religion or morality as a ground for political violence.